COLUMBIA, South Carolina (AP) -- Overwhelming support from Black voters fueled Barack Obama to a decisive win over Hillary Rodham Clinton in South Carolina's primary, a boost to his campaign just 10 days before a coast-to-coast presidential nomination competition in which nearly half the U.S. states will vote. Former Sen. John Edwards, who has yet to win any of the early state contests, finished third Saturday, a sharp setback in his native state, where he triumphed in the 2004 campaign. Landslide margins among Black voters fueled Obama's win, allowing him to overcome the edge that Clinton and Edwards had among whites in the first Southern state where the Democrats competed. The turnout of more than a half-million voters was a new record for the state party. The Democrats quickly shifted their focus to Feb. 5, when 22 of the 50 states hold contests in a virtual nationwide primary dubbed "Super Tuesday." The races offer more than 1,600 convention delegates, a huge amount toward the total of 2,025 delegates are needed to secure the party nomination. South Carolina offers 45. Clinton flew to Nashville on Saturday as the South Carolina polls closed. "Now the eyes of the country turn to Tennessee and the other states voting on Feb. 5," she said, adding that "millions and millions of Americans are going to have their voices heard." Even as he savored victory Saturday in South Carolina, Obama had his sights on Super Tuesday: "Nearly half the nation will have the chance to join us in saying that we are tired of business-as-usual in Washington, we are hungry for change, and we are ready to believe again," he said at his victory rally. Edwards said Saturday night that he is forging ahead to next month's primaries with a belief that the "dynamic could shift at any time." But, he acknowledged: "To win the nomination, I've got to win a contest, of course." South Carolina's Democratic race was particularly significant for Obama, who is aiming to become the country's first Black president, because it was the first contest in which Blacks were expected to be a large factor in the outcome. The runup to South Carolina was marked by a week of mud-slinging between Clinton and Obama, with the two candidates exchanging pointed jabs and accusations as Clinton's husband, former President Bill Clinton, weighed in on his wife's behalf. That prompted Obama to complain that he felt he was running against two Clintons. The loss was not unexpected for Clinton, although she is the leader in national polls. Her husband downplayed the likelihood of her carrying a state where Obama would carry the support of Blacks. Each side accused the other of playing the "race card." Clinton campaign strategists denied any intentional effort to stir the racial debate. But they said they believe the fallout has had the effect of branding Obama as "the Black candidate." By week's end, one poll indicated that Obama's support among Whites in the state had dropped sharply. Blacks accounted for about half of the voters, according to polling place interviews, and four out of five supported Obama. Black women turned out in particularly large numbers. Obama, the first-term Illinois senator, got a quarter of the White vote while Clinton and Edwards split the rest. "The choice in this election is not about regions or religions or genders," Obama said at a boisterous victory rally. "It's not about rich versus poor, young versus old and it's not about Black versus White. It's about the past versus the future." The audience had chanted "Race doesn't matter" while they awaited Obama's appearance. Nearly complete returns showed Obama winning 55 percent of the vote, Clinton gaining 27 percent. Edwards had 18 percent and won only his home county of Oconee. Obama also gained 25 convention delegates, Clinton won 12 and Edwards eight. Clinton, who is aiming to become America's first woman president, issued a statement saying she had called Obama to congratulate him on his victory. The victory was Obama's first since he won the kick-off Iowa caucuses on Jan. 3. Clinton, a New York senator and former first lady, scored an upset in the New Hampshire primary a few days later. They split the Nevada caucuses; she won the turnout race and he gained a one-delegate margin. Obama on Saturday gained an endorsement from Caroline Kennedy, who likened him to her late father, President John F. Kennedy, in an opinion piece in The New York Times. "I have never had a president who inspired me the way people tell me that my father inspired them," Caroline Kennedy wrote. "But for the first time, I believe I have found the man who could be that president -- not just for me, but for a new generation of Americans." Meanwhile, the Republicans campaigned in Florida, where a primary Tuesday will be their last major contest before Super Tuesday. Senator John McCain and former Massachusetts Governor Mitt Romney have been locked in a close fight for the lead in polls. McCain received a key endorsement Saturday from Florida's Republican governor, Charlie Crist. In a heated exchange Saturday, McCain accused Romney of wanting to set a timetable to withdraw U.S. troops from Iraq, drawing immediate protest from his rival, who said: "That's simply wrong and it's dishonest, and he should apologize." In Orlando, Rudy Giuliani, the former New York City mayor who is trailing in polls and trying to climb his way back into the leaders pack, sought to take the high road, saying he wanted to "remain positive."